TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker and becoming a Supporting Member. For more info: Support TMC

If Tesla Motors had a single message to convey at the 2011 Detroit Auto Show, it was this: We're a real car company.

Rather than show a completed prototype of its Model S all-electric luxury sports sedan, scheduled to launch by the end of 2012, the company showed the car's shell.

That allowed other carmakers to look it over, see that it wasn't based on any other company's platform or structure, and pass their own judgment on the structural engineering, suspension design, and of course the slimline battery pack that forms the floorpan.

And visit they did, including no less a luminary than Toyota CEO Akio Toyoda, who ran his hands over the shell and was photographed feeling inside a pillar of the Model S body on display.

We spoke with Tesla VP and chief engineer Peter Rawlinson, whose team is responsible for the design and production engineering of the Model S.

What's the biggest misconception you find people to have about the Tesla Model S?

Peter Rawlinson: We wanted to show that the vehicle engineers at Tesla are capable of designing and engineering a world-class car from a clean sheet of paper. That means engineered in-house, no carryover component assemblies, doing the entire platform, suspension, and body structure ourselves.

We may bring in individual components--brake disks and calipers, electric power steering motors, air suspension, anti-lock brake controllers, for example--but we tune them all ourselves.

Maybe in some quarters, our ability to do all of this isn't as well understood as it might be. So we have to demonstrate that by showing the bodyshell.

During your press event, you used the phrase "aluminum intensive" many times. Can you be more explicit?

PR: The structure of the Tesla Model S is roughly 97 percent aluminum. Weight saving is at a premium for electric-vehicle range, so we've tried to create some elegant engineering solutions to the design challenges--although, of course, never at the expense of safety.

We use a few specific elements made of high-strength steel in, for example, the B-pillars (between the front and rear doors).

The bumper systems are ultra-high-strength boron steel, which is so strong it can't be stamped at room temperature--it has to be heated until it's cherry red before you can form it.

Other than that, we'll do our own aluminum stampings in-house and have specialists do the castings and extrusions. We'll assemble all of them into a complete Model S body.

You've talked about "alpha" and "beta" designs, which aren't auto industry terms. What do you mean?

PR: Alpha vehicles are notionally 80-percent representative of the production vehicle we intend to build. Beta cars are 90 to 95 percent representative.

Not all the systems will be at the same stage of development in each phase. The suspension is all there already on this alpha body, and so is the body structure.

We have four alpha cars identified to crash-test, along with more betas. We don't necessarily have to wreck them that early; it's to verify that our work and modeling bears out, to correlate our computer-aided engineering (CAE) models to actual performance. The beta cars give us deceleration-pulse data to time the airbags.

What's been the most challenging part of designing the Model S so far?

PR: It's been balancing the growth of a new team while simultaneously designing and engineering a brand-new car, in an extraordinarily tight time frame. We're now a team of more than 100 engineers. You could almost think of it as difficulty cubed.

Many companies would balk at simultaneous design of a new platform and a new powertrain configuration. We're adding a new and unconventional type of platform architecture, with the battery pack in the floor as an integral component of the car's safety structure.

We're particularly proud of the pack, in fact. It works both electrically and mechanically, with cells grouped into bricks, bricks into modules, both in parallel and in series.

It was a challenge to get the geometry of the electrical components to fit within the mechanical requirements of the pack layout: Where to put the seat-belt mountings, for example, so you can have through-bolts, and where to place the cross-members to contribute to the side-impact crash structure.

And your biggest remaining challenge in getting the car out the door?

PR: We're focusing on delivery of the program we laid out. We've got lots of bases covered already.

Our crash tests will start soon, and carry on in phases through 2011.

But, frankly, we're on track. We know what we're doing.

Click to expand...

What a great article!!! It lays out a much clearer path after the NAIAS presentation. I think Tesla Motors is here to say and EVs are the future.

Yeah, I didn't think it had J1772. It didn't look like J1772 to me either.
Yes, it would be nice to see J1772 on the Alpha prototypes to put the question to rest.
But they could still use Tesla connector for now (since they have so many charging stations installed at their offices), and switch to J1772 for Beta or production.

Yeah, I didn't think it had J1772. It didn't look like J1772 to me either.
Yes, it would be nice to see J1772 on the Alpha prototypes to put the question to rest.
But they could still use Tesla connector for now (since they have so many charging stations installed at their offices), and switch to J1772 for Beta or production.

Click to expand...

That's the way I see it. Everything they have is Tesla so use a Tesla. We might start seeing the J connector when they announce/offer the Roadster fix. Then they would have to start putting in dual charger/adapters in the stores.

dsm363,
I think Tesla Motors will move in that direction if the J1772 inlet is or becomes the standard for charging an EV.

Click to expand...

There is no "if," J1772 is both the official standard and the dominant de-facto standard.

In the US, J1772 is the official standard. Soon there will be 20,000 public Level 2 J1772 charging stations spread across a dozen metro areas, compared to about 20 public Tesla charging stations mostly in California. Even in the Seattle area, where the only "public" Tesla charging station is in the Tesla store and not available 24/7, the Tesla chargers are already outnumbered with just four early adopter ChargePoint installations (7 units) in Bellevue, Redmond, and Woodinville. Now that ECOtality has UL approval on their Blink charger, the floodgates are about to open. Even with less than 1% of the federally funded J1772 chargers in the ground, if they don't already outnumber the public Tesla chargers, it's only a matter of days or weeks before they do.

Even though these federally funded stations only provide 240V/30A, it will be easier to get full 80A J1772 chargers installed than it is to talk business owners into providing chargers exclusively for the minority of Tesla owners.

Tesla has been very generous donating HPWCs for a few critical charging locations. I-5 is enabled for Roadster driving from BC to LA with chargers every 100-150 miles. The referral program that gifts an HPWC to Tesla owners who refer new customers who purchase Roadsters has allowed us to put chargers in spots of interest to local owners. This is all great stuff, but it can't compete with federal funding and the market forces behind the hundreds of thousands of EVs that the big automakers plan to put on the roads in the new few years.

I really do not understand, even american power networks are trying to move their customers toward 3-phase power up to 480V to match the demand for high power application?
With more EV on the road it makes sense to power then with 3-phase as well. Therefore J1772 is an dead end.

I really do not understand, even american power networks are trying to move their customers toward 3-phase power up to 480V to match the demand for high power application?
With more EV on the road it makes sense to power then with 3-phase as well. Therefore J1772 is an dead end.

Click to expand...

I think you may be underestimating how long it will take for the average American house to have readily accessible 3-phase power.
It is definitely different than Europe here. I think it could be decades away if ever.

I expected, america has the best and most advanced technology first - it took around 10 years - in the sixties when the german grid was upgraded from 110 to 220/380 now it is 230/400

Click to expand...

The grid is actually none of these voltages, in America or anywhere of any significance. The grid is anywhere from a few thousand to many hundreds of thousands of volts. The final voltage delivered to your home is determined by the transformer located just a short distance from your house.

I am fairly certain that there are very few homeowners in the USA that would have the slightest desire to rewire their homes and replace all of their electrical devices and appliances with units that they would have to import from distant locations.